In the current 3D sensing technology, 3D measurement is mainly performed through a triangulation method and a time delay method. At present, three 3D sensing technologies, i.e., a stereo vision technology, a structured light technology, and a time of flight (ToF) technology have advantages in price, volume, and performance.
According to the structured light technology among the three 3D sensing technologies, a structured light pattern is projected to a to-be-tested object, and a camera or another image capturing device is applied to capture image information to measure the distance, thereby obtaining the 3D information of the to-be-tested object. Therefore, how to design a useful structured light with high resolution is one of the research topics to which people skilled in the art endeavor.